The Knicks have offered future second-round picks and future considerations (cash) to Portland in an attempt to regain the rights to small forward Kostas Papanikolaou, according to sources.

The Trail Blazers have rebuffed the Knicks and were asking for their 24th pick in a swap with Portland’s 39th pick Thursday night to pony up the 6-foot-9 Greek. Knicks general manager Glen Grunwald isn’t looking to give up his first-round pick, though some draft experts consider the 24-to-39 range rather comparable in a draft weaker than last season’s.

The Knicks drafted Papanikolaou last June in the second round with the 48th overall pick, telling the media he would be ready to arrive in the NBA for the 2013-14 season. But in desperation, with almost no assets left, Grunwald dealt Papanikolaou in the Raymond Felton sign-and-trade so he could avoid matching Jeremy Lin’s monster contract offer.

According to sources, Papanikolaou, who won his second straight Euroleague championship for Olympiakos last month, is being shopped by the Blazers — at the request of his agent, Marc Cornstein.

The Blazers don’t want to bring Papanikolaou in for the coming season and pay the $1.1M buyout to Olympiakos. Portland has two international small forwards currently in Frenchman Nicolas Batum and his backup, Spain’s Victor Claver.

Papanikolaou, 22, would fill a need for the Knicks as a small forward who can defend and shoot from the perimeter — a skill in which he improved immensely in the past year. Papanikolaou shot 52 percent from 3-point range in the Euroleague. Grunwald scouted Papanikolaou during the Euroleague Final Four in London last month.

According to sources, Portland has received offers for Papanikolaou from others teams with picks in the late 20s. It appears Portland GM Neil Oshey wants to wait until draft night to determine who is available. The Blazers believe if Papanikolaou were in this year’s draft, he’d easily be a first-rounder.